How do parrots talk, and do they understand what they say?

Parrots produce speech through a completely different mechanism from ours, and the question of understanding has a more interesting answer than either extreme.

The mechanism. Birds have no larynx or vocal cords. They use a syrinx, located where the trachea splits into the bronchi. Because it sits at a junction, it has two independently controllable sides, letting some birds produce two pitches at once. Parrots shape sound further using an unusually thick, muscular tongue — far more mobile than most birds' — and by modifying the vocal tract. They imitate human speech without lips or teeth by controlling tongue position and tracheal length.

Why they do it at all. Parrots are highly social and live in flocks with learned contact calls, sometimes described as vocal signatures. Mimicry is how a wild parrot integrates with its group. A captive parrot's flock is its humans, so it learns the sounds its flock makes — which is also why lone, under-stimulated parrots often mimic most.

Do they understand? Usually not in the way an owner imagines. Most mimicry is associative: a phrase becomes linked to a context or an outcome, much like any conditioned behaviour. A parrot saying "hello" when the door opens has learned a reliable association, not the concept of greeting.

But the ceiling is higher than that. Irene Pepperberg's decades of work with Alex, an African grey, demonstrated performance on tasks involving categories, colours, shapes, quantities up to six, and the concept of same and different — and apparently a grasp of zero. Alex could answer novel questions about objects he had not been trained on. The work remains debated in its interpretation, but it established that some parrots handle genuine abstract concepts rather than pure imitation.

African greys, amazons and budgerigars are the strongest mimics; budgies hold the record for vocabulary size.